Prism Questions

A spectrometer gives the following reading when used to measure the angle of a prism.Main scale reading: $58.5$ degreeVernier scale reading: $09$ divisionsGiven that $1$ division on main scale corresponds to $0.5$ degree. Total divisions on the vernier scale is $30$ and match with $29$ divisions of the main scale. The angle of the prism from the above data is: